Electronic journals (E-journals) are popularly and extensively used in academic libraries. They involve a variety of publishers, aggregators, database producers, abstracts, and indexing services with different charging systems. In view of the various elements of E-journal composition, the evaluation of E-journals is necessary and significant. This paper mainly discusses the issue of E-journal evaluation by exploring the applications of E-metrics and performance assessment. This subject of study includes researches on evaluation indicators, evaluation procedures, data collection, data usage analysis, usage reporting, and usage statistics. Three case studies are involved in this paper, including the application of usage-based metrics on evaluation executed by the University of Maryland, the ARL E-metrics project, and the analysis of E-journal usage carried out by the University of Nevada, Reneo. The results acquired from this study suggest that E-metrics and performance assessment may serve as beneficial methods for E-journal evaluation while applied to multiple contexts of libraries and their parent institutions. They may significantly create new models of E-journal management.